CPR Basics

CPR is a first-aid technique used to keep victims of sudden cardiac arrest and other emergencies alive and to prevent brain damage until more advanced medical professionals can arrive. Traditional CPR has two goals: to keep oxygen flowing in and out of the lungs and to keep oxygenated blood flowing throughout the body.

While the modern emergency room has high-tech equipment and an arsenal of drugs to help treat people who are experiencing heart and breathing emergencies, CPR is a simple technique most anyone can do with little or no equipment.

There are different types of CPR, and the one you perform on a person depends on your level of training and your access to additional lifesaving aids. The following are varying levels of CPR broken down by the Mayo Clinic:

Untrained persons -- If you've never been taught CPR, you should perform hands-only resuscitation (we'll discuss this more in detail later), which requires applying uninterrupted chest compressions at a rate of approximately 100 compressions a minute until emergency personnel arrive.

Trained, but rusty -- If you've been trained in CPR but are unsure of your skills, experts recommend that you use the hands-only method.

Trained and confident -- If you've taken a CPR class and are prepared to administer resuscitation, you should perform compression CPR in coordination with rescue breathing.

Trained with access to an automatic external defibrillator -- Deliver one shock with the AED according to the device's instructions and then begin CPR.

When it comes to CPR, comprehensive training is ideal, but even some knowledge is better than no knowledge at all. In fact, hands-only CPR is just as effective as traditional CPR in the first few minutes following an attack [source: Mayo Clinic]. In the next section, we'll go over the step-by-step basics of CPR so you can be better prepared to help others in case of emergency.

The purpose of emergency rooms is to save lives, but they're more complex than we think. Treating a range of illnesses from cardiac arrest to the common cold, emergency health experts act quickly to get patients the treatment they need. Test your knowledge of emergency rooms with this quiz.

You just got a new job. You go in on your first day, get your ID badge and fill out all of your paperwork. You start work immediately, but your insurance doesn't start working for you for another 30 days. Why do you have to wait?